The idea would be to publish a dashboard, with all of the complex visualizations, and then allow the end user to ask questions on the dashboard.
Additionally, all filters that apply to the dashboard, could automatically be applied to "ask data" if the analyst creates it this way.
This could be incredibly powerful and useful if the analyst creates table calculations based on parameters. If this is the case, the end user can see how changes in the parameters not only change the already created visualizations, but their specific calculations as well.
So let's say you have a chart showing projections, and one of the parameters are "% growth in sales". The end user would be able to ask "sum of monthly growth" and get a new bar chart, depedning on what they added to "% growth in sales". And if they are already looking at a specific store, the Ask Data box will automatically filter for that store as well. All within the dashboard the end user is already looking at.
And since it's in dashboard, I assume you would be able to see this on every version of tableau!